textproduct: Rapid City

KEY MESSAGES

- Mild, dry and breezy this afternoon. Wind gusts occasionally up to 45 mph possible

- Strong winds likely Tuesday. A High Wind Warning is now in effect for most of western SD

- Turning colder with chances for light snow across the region Wednesday through Friday

UPDATE

Issued at 803 PM MST Mon Dec 8 2025

Have upped wind speeds over northeastern WY per latest deterministic guidance in combination with earlier probabilistic guidance. 00z NAM Bufkit soundings/HRRR suggest high wind warning winds over northeastern WY Tuesday, but MOS not as excited with best isallobaric forcing (4-5mb/3hr pressure rises) over western SD. NBM depicts <20% chance of >=58mph gusts for northeastern WY. Western SD plains have the expected high probabilities. Thus, the current wind headlines look good. Midnight shift can take one more look before strong cold front arrives.

DISCUSSION

(This Evening Through Monday) Issued at 1247 PM MST Mon Dec 8 2025

Rest of today...Not much going on across the region this afternoon. A weak wave is passing through which has kicked up the winds a bit over the last hour. These breezy conditions will continue for several more hours before they diminish. Winds could occasionally gust up to 45 mph with mild temperatures.

Heading into Tuesday morning a stronger area of low pressure will bring a surface front through the region during the early morning hours and ahead of the main wind event. This will provide a window for some light snow or a rain/snow mix to occur across the northwestern portions of the area. Expecting a quick transition to all rain as the strong downsloping winds develop which will quickly warm temperatures. This area of low pressure will slide to the SE across central ND and SD Tuesday. A belt of 55-60 not winds will overspread the region quickly and winds are expected to turn gusty rather quickly during the morning hours on Tuesday. a suite of HI-RES models have come in a bit stronger with these winds aloft around the 850mb level showing a concentrated area of 70+ knot winds across the eastern plains. While these winds aloft are impressive the strong CAA advection we were expecting has not been pushed off to the north and east and this will limit some mixing down of these winds. But precipitation post frontal boundary will linger across the region in the form of banded lines of rain showers. These will be a concern as locations under these areas of precipitation may see sudden bursts of rain/snow, snow or, graupel as well as strong wind gusts as those strong winds aloft will mix down with the precipitation. Outside of that, much of western SD and the eastern Plains will experience strong winds throughout much of the day on Tuesday with wind gusts commonly exceeding 60 mph with a few locations seeing wind gusts at or over 65 mph. Given this a High Wind Warning is now in affect for Tuesday morning through late Tuesday night.

Another system is on the heels with the exiting system with unsettled weather expected to persist Wednesday through the rest of the week. Models are beginning to settle in on the overall long wave pattern but the mesoscale parameters that will determine how quickly we transition to all snow, how strong the CAA will be and surface flow still need to be ironed out to pinpoint just how much snow will fall and where the heaviest snow will occur. The overall consensus at this time is for widespread snow looks likely with light accumulations possible. With this pattern shift temperatures are also expected to turn colder as CAA eventually advects into the region. This will drop highs into the upper teens to lower 20s with overnight lows in the single digits.

AVIATION

(For the 06Z TAFS Through 06Z Tuesday Night) Issued At 1005 PM MST Mon Dec 8 2025

VFR conditions are expected through 09/12z. A strong cold front will move through Tuesday bringing strong, gusty northwest winds behind it, reaching 50-55kts on the western SD plains at times after 09/15z. Areas of MVFR/IFR conditions due to lower clouds/ra/sn will affect northeastern WY/northwest SD behind the front. Mainly VFR conditions expected over southwest into south- central SD.

UNR WATCHES/WARNINGS/ADVISORIES

SD...High Wind Warning from 8 AM MST /9 AM CST/ Tuesday to 2 AM MST /3 AM CST/ Wednesday for SDZ001-002-012>014-025>027-030>032- 041>044-046-047-049-072>078. WY...High Wind Warning from 8 AM Tuesday to 2 AM MST Wednesday for WYZ060.